Robots can exert forces on their environment—for example, in joining operations—or unintentionally as well—in a collision for example—wherein, for a more compact design, anti-parallel pairs of forces are also present, i.e. torques, that in general are referred to as forces.
According to operating parameters, it is thus known to detect joint forces τ and to evaluate model-based externally induced joint forces {circumflex over (T)}e that result in the joints by a contact of the robot with the environment.
With kinematically redundant robots, working forces {circumflex over (f)}W in the workspace between a robot-permanent reference point, in particular the TCP (Tool Center Point) of the robot, and the environment, can be evaluated and monitored based on these joint forces, in particular by means of a so-called pseudoinverse of the transposed Jacobian matrix (JT)#:{circumflex over (f)}W=(JT)#·{circumflex over (T)}e 
If the working force evaluated in this manner exceeds a threshold value at the TCP, a safety reaction is triggered, such that the robot is shut down, or moved back, for example.
In particular, measurement and modeling inaccuracies, which act on the pseudoinverse (JT)# can lead thereby to errors for the evaluated working force {circumflex over (f)}W at the robot-permanent reference point. Additionally, or alternatively, joint torques can be projected erroneously on a fictitious working force {circumflex over (f)}W acting on the TCP, due to contact forces acting on a point on the robot spaced apart from the TCP. In particular, if the joint forces resulting from this contact force spaced apart from the TCP are substantially located in the null space of the pseudoinverse of the transposed Jacobian matrix, then a quantitatively very small working force is evaluated and no safety reaction is triggered.